1. Field of the Invention
The present invention relates to a method and system for displaying X-ray images in blood-vessel stricture parts of a subject.
2. Description of the Related Art
Conventionally, a recovery operation for a blood-vessel stricture part of a subject is performed by inserting a catheter toward the blood-vessel stricture part, locating a balloon attached to the catheter at the stricture part and then expanding the balloon. By this operation the blood-vessel stricture part can be restored to the previous diameter.
The above-mentioned operation is performed while an X-ray image of the blood-vessel stricture part of the subject is displayed on a television monitor and the displayed image is observed by a doctor. Otherwise a new type of apparatus is used for catheter operation which has been developed because of advances in image processing techniques resulting from the recent spread of integrated-circuit (IC) memories. According to this apparatus, as shown in FIGS. 1A and 1B, contrast image 20, which well reproduces a blood-vessel stricture part, is previously stored in an IC memory, the contrast image is then converted into analog information to be displayed on television monitor 21, and a doctor operates a catheter while comparing the contrast image with X-ray image 23 displayed on X-ray monitor 22.
With such apparatus, however, by the comparison between contrast image 20 of blood-vessel stricture part displayed on TV monitor 21 and X-ray image 23 of catheter 25 with balloon 24 displayed on X-ray monitor 22, the doctor will only assume the true position of blood-vessel stricture part on X-ray image 23. Thus, it is difficult to know the accurate positional relation between blood-vessel stricture part and catheter 25 having balloon 24, and the operation of catheter 25 is not easy.
Moreover, although contrast image 20 of blood-vessel stricture part is displayed as a still image on TV monitor 21, since the blood vessel moves actually in accordance with the heart beats of the subject the still-image display alone will not permit sufficient operations of catheter 25.
Thus, the apparatus is desired which can definitely display a positional relation between a blood-vessel stricture part and a catheter with a balloon.